Whether making square or flat stock, the jointer and planer work together to get it right. Click image to enlarge

Preparing Stock with the Jointer and Planer

The sequence to flat, square material

Text & photos by Tom Hintz

   Using straight, square wood with parallel sides is crucial to producing quality projects. If the wood used to build your project is crooked, your project is likely to be crooked as well. Having a jointer and surface planer in the shop can remedy these problems providing that we understand their capabilities, limitations and the sequence in which they should be used.

The Machines

   The jointer was designed to flatten the surface of wood and square adjacent sides using the built-in fence. While squaring all four sides in relation to each other is possible, the jointer cannot insure opposing sides are parallel to each other on the long axis.

   A surface planer not only reduces thickness, it cuts the upper surface with a set of knives that are parallel to the bed on which the material slides. If the bottom of the piece being cut is flat, the planer will cut a parallel surface on the top. If the bottom surface is crooked, the knives will replicate that defect on the top surface.

   Using the capabilities of the jointer and planer in the proper sequence results in exceptionally straight, square and consistent lumber.

Preparing the Wood

   Before going to any machine, be sure to look the wood over for staples and other metal bits. There is no surer way to ruin the knives in your jointer or planer (not to mention the table saw blade) than machining wood containing a piece of metal.

   We can make these operations easier and faster by preparing the stock before going to the jointer and planer. Preparation is especially important when using the smaller jointers and planers often found in the home workshop.

   Cutting the pieces to rough length, within an inch or two of the final length is important for two reasons. Machining two 4'-long pieces is easier to process accurately on short bed jointers than one 8'-long board. Also, until the sides of the wood are square and parallel, we cannot trim the ends square accurately.

   Boards with badly bowed edges should have the majority of that defect removed using a jointing jig on the table saw. The jointer could eventually remove a large bow but that would require a large number of cuts and would probably waste more wood than using the table saw jointing jig.

Making sure your machines are properly set up before starting this operation is a must! Click image to enlarge

The Sequence

   The wood in the photos is a glue up, made from a pair of 1 ½"-thick by 3 ½"-wide pieces. While this glue up will become a square blank for a table leg, the sequence of cuts is the same for flat stock like a common 1 by 6.

   When machining a glued up piece of wood, the first cut should be made on one of the solid sides, not the edge with the glue line. If the pieces were not perfectly aligned when glued the flat created by the jointer can be badly out of line with the rest of the piece. When that happens, an excessive amount of wood has to be removed to make the remaining sides square.

   I have found that by making the first cut on one of the wide sides (side A in the photos), the whole process is easier. The wider surface is much easier to hold flush against the fence for the second cut, making that part of the operation more accurate.

   Remember to pay attention to grain direction when using the jointer and planer. The cutters must be working down the grain to produce a smooth surface. For more on grain direction see the Resources section at the end of this story for a dedicated story on reading grain.

(Top) Cut one, wide face down, establishes a straight face. (Middle) cut two, turning side A against the fence lets you make side B flat and 90-degrees to side A. (Bottom) Cut three is usually done on the table saw to bring side C into parallel with side B. Click images to enlarge

Cut One - Jointer

   With the A side on the jointer bed, take light cuts until that entire face is flat.

Cut Two - Jointer

   Note: Use a square to make sure the fence is exactly 90-degrees to the jointer table. The cut can only be as accurate as this setting so check it regularly!

   Turn the piece so that side A is against the fence and either side B or C (dependent on grain direction) is on the jointer table. Holding side A flat against the fence, take light cuts until the bottom surface is completely flat to the jointer bed, and perfectly square to side A.

Cut Three - Table Saw (Usually)

   Moving to the table saw for the third cut is often easier and faster. If all four faces of the workpiece are relatively wide and nearly square after cut two, we might be able to go right to the surface planer. In most cases, especially with flat stock, the table saw is the best tool.

   By placing the edge (B or C) machined in cut two against the table saw fence and side A on the table surface we can accomplish two things in one pass. The width can be rough sized and edges B and C made parallel in one cut. In many cases a considerable amount of wood must be removed, a task the table saw handles easily in a single pass where the jointer or planer could require many cuts.

   Adjust the fence for a cut about 1/16" wider than the final dimension and carefully make the cut.

Cut Four - Jointer and Planer

The planer makes the sides smooth, and parallel. Alternate between adjacent sides and the piece is made exactly square also. Click image to enlarge

   If the work piece is a flat board, like a 1 by 6, return to the jointer and make a 1/16"-deep cut to smooth the edge cut at the table saw and reduce the board to its final width. Because the edge was cut parallel and straight at the table saw, making one or two passes on the jointer will not substantially change the edge.

   Caution: Some woodworkers clamp several thin boards together and send them through a surface planer on edge, clamps and all. Aside from the obvious dangers of sending clamps through the planer, this is a very unreliable way of cutting edges that are truly square to the wide faces. Machining the narrow edges of the boards individually on the jointer is the best bet.

   When making a square piece of wood we can usually skip this jointer cut and go right to the surface planer.

Cut Five - Surface Planer

Reading grain direction and taking light cuts will produce fine results. Just because the depth indicator says you can remove a bunch of material at once doesn't make it wise to do! Click image to enlarge

    Now that the edges of a flat board are square to side A, we can use the planer to make side D square to the edges and parallel to side A.

   If the board is flat like a 1 by 6, place side A down on the bed of the planer and take light cuts from side D until it is flat and the board is reduced to the thickness desired.

With a square workpiece, we also put side A down on the planer bed and make a light pass. Before changing the planer height, turn the stock 90-degrees so the previously jointed edge is facing down on the bed and run it through the planer again. This makes the piece square.

   If more material has to be removed, lower the cutting head 1/16" and make two passes, turning the piece 90-degrees between them. Continue making light cuts, turning the piece between each pass until the workpiece is reduced to the dimension desired.

   After planing the piece to the desired dimension you can trim it to length, confident the freshly cut ends will be square to the sides.

   Following this sequence not only helps your machines produce flat, square material, it saves time and money. The amount of wasted wood is reduced and there is less wear and tear on your machines.

   Most importantly, you are better able to produce standard and custom wood sizes that will enhance the projects you build.

Resources

Table Saw Jointing Jig
Reading Grain Direction

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